I am also delighted to report that for the second time this year (which is to say, like “The Third Mind”) a major museum show has paid proper attention to the fundamental importance of performance art to the story that it tells. I trust that this is a harbinger of a shift in curatorial perceptions because, like a number of my best friends, I have spent my entire professional life banging my head against an unsympathetic orthodoxy that imagines that performance art is a curious minority interest. Plan to spend a good couple of hours at the Whitney, because that will give you the opportunity to experience the room filled with the films of Mr Oldenburg’s early-sixties happenings that my compatriot Chrissie Iles has put together. Without boasting I can say that I know as much about happenings as almost anyone on this planet, and I haven’t seen any of these films before. In fact some of them have never been shown since they were made. Mr Oldenburg is all too aware of the special status of his performances. At this morning’s press view of the show he praised Ms Iles’ decision to show a number of films simultaneously around the walls of a single darkened room, and went on, “You stand in that room and you’re looking at something, and then you’re aware that you want to look at something behind you, and then you turn around and you realize you’ve missed something else and so you turn around again. I said to Chrissie she should have just one big pillow in the middle of the room so that the viewer could toss and turn. And that might also bring them closer to the notion that what they are in there is really the unconscious. I would say that the rest of the show is pretty conscious, but that room is really rather frightening, especially since I know many of the origins of what’s going on in there.”

It may well be that one of the surprises that this show will offer many visitors – and without surprises what show can lay claim to genuine significance? – that a performative element is basic to Mr Oldenburg’s entire artistic output. Almost all of his work – and certainly all of the sculptures included here – at least imply movement in one way or another. (One in particular, the wheezing and lumbering Ice Bag – Scale C (1971) actually moves in a fairground-ish sort of way and will prove a great crowd pleaser as a consequence.) This morning Whitney director Adam Weinberg quoted Mr Oldenburg as saying, “If you are true to the art process, it is by its nature metamorphic,” before pointing out that, “These works do seem to change before our eyes. They seem like they’re in the process of moving, falling, changing, dripping, melting, climbing, descending … You really do get that sense.”

Claes Oldenburg, "French Fries and Ketchup" (1963)

Another surprise comes with the revelation that an artist best known for apparently happy-go-lucky giant soft sculptures – that seem not only quintessential works of pop art, but also quintessential products of the sixties – actually had his artistic beginnings in a darker, rather more romantic relationship with the American urban working classes. This is made obvious by those happenings films, but also by all of drawings, sculptures, posters, and other paraphernalia that relate to the unique collision of art and life that was his Store, aka The Ray Gun Mfg. Co.

Claes Oldenburg, "Poster for The Store" (1961)

This was an actual functioning store that Mr Oldenburg operated down on East 2nd Street for the month of December 1961, and in which he made, and attempted to sell, his plaster covered chicken-wire sculptures of shoes, shirtfronts, food, and underwear. In fact I have sometimes thought that it was in this bitter and far from celebratory art of the very early sixties that Mr Oldenburg made some of his most telling statements. He hinted as much himself this morning when he admitted that, “By 1962, things had pretty much exhausted themselves.” For most people this will be a significant corrective to the absurd notion that, like the other pop artists, Mr Oldenburg was simply concerned with the surface of things (after all it was only Andy Warhol that even claimed that). In fact, he is one of the most erudite and penetrative artists of the modern period, whose artistic language is rich in cruel literary and visual puns, and for whom the echoes of a collapsed human body in his famous Soft Toilet of 1966, or the suggestion of a puking mouth in the oval of its seat are every bit as tragic as they are comic.

Claes Oldenburg, "Soft Toilet" (1966)

Another kind of tragedy is most obviously present in the second of these shows-within-a-show, the installation of elements from The Music Room that Mr Oldenburg made in collaboration with his wife Coosje van Bruggen, who – though his junior by 13 years – died earlier this year. Ms van Bruggen was a major art world figure in her own right and, from the mid-1970s, a genuine equal player in their artistic partnership, particularly in the conception, planning and execution of the Large-ScaleProjects for which she and Mr Oldenburg are best known in many circles. The Music Room sculptures, made for the actual salon of their chateau in eastern France, have a quite different character to the earlier work in the other half of the show, and it is clear how deeply Mr Oldenburg still mourns Ms van Bruggen when he talks about her not being able to see this show.

Claes Oldenburg and Coosje van Bruggen, "Soft Viola" (2002)

What is also a little bit sad is that the powers that be at the Whitney don’t seem to have realized what a fantastic show they have on their hands here. Most of the work included here is from their own holdings, or from the Oldenburg-van Bruggen collection, and so they haven’t gone to the trouble of publishing a catalog. That is a shame. Perhaps they might be persuaded to publish those happenings films on a series of DVDs instead. Now that would really be a reflection of their importance.